This invention relates to ultraviolet curable coating compositions and to a method for preparing and curing same. More particularly, this invention relates to a method for improving the cure response properties of ultraviolet radiation curable coatings.
Ultraviolet curable coating compositions utilizing titanium dioxide or other metal oxide pigments have been deficient in cure rates and cure response. This is thought to occur because of the ultraviolet reflection and absorption characteristics in certain ultraviolet wave lengths of titanium dioxide type pigments. Thus, it has been partically impossible to utilize titanium dioxide in ultraviolet curable coatings compositions. Likewise, many photoinitiators, such as, for example, benzophenone, benzyl, thioxanthone, and the like, are extremely expensive and the amounts of these materials required have greatly increased the cost of ultraviolet curable coating compositions.
Thus, it is an object of this invention to prepare ultravoilet curable coatings containing titanium dioxide-type pigments which exhibit normal cure response properties.
It is another object of this invention to prepare inexpensive ultraviolet coating compositions.
It is another object of this invention to prepare ultraviolet curable coating compositions which require smaller amounts of standard ultraviolet photoinitiators.